Re: [PATCH 1/2] Bluetooth: Add locking scheme to timeout callbacks.

[Andrei Emeltchenko <andrei.emeltchenko.news@xxxxxxxxx>]

Hi,

On Mon, Aug 24, 2009 at 5:45 AM, Gustavo F. Padovan
<gustavo@xxxxxxxxxxxxxxxxx> wrote:
> Avoid race conditions when acessing the sock.
>
> Signed-off-by: Gustavo F. Padovan <gustavo@xxxxxxxxxxxxxxxxx>
> ---
>  net/bluetooth/l2cap.c |    4 ++++
>  1 files changed, 4 insertions(+), 0 deletions(-)
>
> diff --git a/net/bluetooth/l2cap.c b/net/bluetooth/l2cap.c
> index c04526f..efac637 100644
> --- a/net/bluetooth/l2cap.c
> +++ b/net/bluetooth/l2cap.c
> @@ -1192,6 +1192,7 @@ static void l2cap_monitor_timeout(unsigned long arg)
>        struct sock *sk = (void *) arg;
>        u16 control;
>
> +       bh_lock_sock(sk);
>        if (l2cap_pi(sk)->retry_count >= l2cap_pi(sk)->remote_max_tx) {
>                l2cap_send_disconn_req(l2cap_pi(sk)->conn, sk);

missing unlock ?

>                return;
> @@ -1203,6 +1204,7 @@ static void l2cap_monitor_timeout(unsigned long arg)
>        control = L2CAP_CTRL_POLL;
>        control |= L2CAP_SUPER_RCV_READY;
>        l2cap_send_sframe(l2cap_pi(sk), control);
> +       bh_unlock_sock(sk);
>  }

Please consider following patch:

--- a/net/bluetooth/l2cap.c
+++ b/net/bluetooth/l2cap.c
@@ -1208,6 +1208,7 @@ static void l2cap_monitor_timeout(unsigned long arg)
        bh_lock_sock(sk);
        if (l2cap_pi(sk)->retry_count >= l2cap_pi(sk)->remote_max_tx) {
                l2cap_send_disconn_req(l2cap_pi(sk)->conn, sk);
+               bh_unlock_sock(sk);
                return;
        }


Also see complete patch attached.

Regards,
Andrei Emeltchenko

Attachment: 0001-Bluetooth-Fix-locking-scheme-regression.patch.gz
Description: GNU Zip compressed data